From the detail page at OppoDigital.com, the PM-1 should have a decent field from two banks of neodymium magnets. The multilayer diaphragm/armature with its spiral conductor(s) could very well drive the price to on or around $1000.00; multilayer printed-circuit sheets are quite expensive to produce and, until recently, the reject rate was a bit highish.
You're speculating on some very ambiguous information. Note that, based on one's interpretation, the diaphragm has either one layer ("a very thin polymer film"), one or two layers ("[t]he double-sided diaphragm"; any single-layer diaphragm is double-sided by necessity), and in a convoluted way seven layers ("[t]he double-sided diaphragm has 7 layers of extremely thin materials").
I think the truth is found in the sentence, "The diaphragm has a spiraling pattern of flat conductors etched on both sides of a very thin polymer film." Whether having a twin voice coil makes it more expensive to produce I don't know; but as some wonder how people expect it to be cheap, I think it's equally valid to wonder why people so readily interpret the ambiguous information in a way that it would not be cheap.